Fixture for machine tools



' w. MELIN Filed Jan. 19, 1942 FIXTURE FOR MACHINE TOOLS 2 'Sheets-Sheetl Snvenfor Clttornegs 2 sheets-sheet 2 .Filed Jan. 19, 1942 Gttomegs lPatented Nov. 7, 1944 UNITED yPiflflf"E151,.Tl '1 OFFICE 1 j 2,362,288'j FIXTURE Fon MACHINE Toons,- 1.

I William Meli, Detroit, Mioh. ApplicationiJanuary 19, 1942, Serial No.427,277

6 Claims;i 01. sieges) Thisinvention relates toV machine toolsand,

in particular', to work-supporting xtules forf 1 milling and grindingmachines, especially for the production of spirally fluted workpieces.

One object of this invention is toprovide1 a' Work-supporting fixturefor machine tools having' means for" spirally rotating the work-holderalonga predetermined path, withmeans for adjustably varying' theposition vof a given 'pointin thejspiral path so as tovary1 thepositions of the flutes on the' workpiece relatively tothe cutter' orgrinding wheel. 1

Another object is to provide a; work`support1 ing fixture formachine'tools having a work-- holder with a spiral gro'oveengaged" by a 'pro-vjectionV which is1 adjustable arcuately1 around the axis of the spiral-fgroove soa's toadjust the position of the work-holder relatively 1'to'the cutter or grinding Wheelf'for'different batches' ofiiutedworkpieces.

ing fixture as set forth in the preceding object wherein the projection'ismounted upon an arcuate toothed member meshing with a correspondingtoothed adjusting member for precisely posi.-

tioning the projection around the axis. of rota-- tion. of thework-holder.y i

Another object isv to. providea vworkfsupport ing. fixture consisting ofa spiral1y,grooved.spin.. dle.V mounted for spiralrotary vmovement .and

having aprojection engageable with the groove 1 and'v mounted upon. anvannular worm gear iengag'ed by a-,worm for. adjustingtheprojectionarcuately around the axis ofA rotation of ther spindle. y 1

Another object is to. provide a work-.supporting xture consisting ofaspirallly movable spinf` wheelbut also optionally serve. aswicks forconveying lubricant to the-bearings.- In the. drawings;

Fig.. 1. isa topplan view partly in section. of

. av preferred embodiment of' theI worlirI-supporting;

fixture for machine tools, accordingy `to .the invvention. a

Fig. 2 is a irontelevationof the-fixture shown`v in Fig. 1, alsopartially in'se'ction..

Fig. 3` is. a longltucllnalsection throoglin'lo" forward, end'. of thework-holding spindle shown.

ih Fig.' 1.

Fig. 4 isla left-hand end elevation of Fig. 1. Fig 5'i'sa1right-hand'endelevation of Fig. 1.

Fig. 6` is a cross-section'1alongfthe line 6 6 in Another object' is toprovide a worklsupportf* 1in-iig. '1 is a seononalong the liner-1 innig.1,

with aspindle bearingbroken away to disclose the wiping member.

Fig. 8`is a side elevation of a vfluted Work-piece,1 such as 1anend1mill`,.prior to being ground whilel held in thework-supporting'fixture of the pres'` entinvention. 1 1 1 Fig. 9 is a1view similar to Fig.4 8; but showing the work-piece after it has beenground" in the? workfsupp'orting fixture of the presentiinvention.'`Fig. 10 is a cross-section through the '-unground work-piece, takenalong the line Ill-Ill in Fig. `8."

Fig. 1.1 is across-section through the ground workfpie'ce, taken alongthe line I'l-I'lin Fig. 9.A

the latter is beingv ground by a grinding wheel' or machined'1 by'acutter. The spindle or arbor is.` mounted in'. spaced 4bearings 1 havingchambers -therein for receiving wiping material which 'presses againstthe spindle or arbor and wipes its surface free from the abrasive dustlfrom the grinding wheel or metal particles from the workpiece. Thewiping material is preferably porous and absorptive so that it may holdthe particles vll'armlessly and reduce wear upon the spindle or bearing.The porous v'materialmay optionally serve as a wickfor conducting'lubricant to the bearings, thus lubricatingthe'spindle or arbor "as wellas wiping it freelfrom abrasive Adust or metal'particles. 1 1

The arbor or spindle is provided with a spiral groove which is `engagedby a linger mounted in a ring gear coaxial" with the axis of thespindle.

The ring'gear in turn is mounted inan annular support and engaged by awormfhaving an -adjusting handle connected thereto. They spindle atits-outer end carries an operatinghandle.

The bed upon vwhich the flxturef'is mounted lis secured to the carriageof the machine tool and so adjusted relatively tothe grinding wheel aslto be properly positioned when a spirallyv fluted workpiece;` such as anend` mill', is placed in the adapter. (Fig. l.) The rotation of the.worm'by' its handle enables' the 'flute of the workpiece` to be.positionedaccurately relatively" t work table or carriage I3 of themachine.

Machine construction Referring to the drawings in detail, Figs. 1 and 2show a machine tool, such as a grinding machine, having a saddle I8which is vertically adjustable relatively to the bed of the machine (notshown) by conventional means (not shown). The saddle I is provided withways II coacting with a dovetailed groove I2 in the A screw shaft I4mounted in bearings I5 and I6 inthe bridge portions I1 and I8 of thesaddle I8 engages the threaded nut I9 which traverses the recess 20between the opposite ways II and is secured to the underside 2| `of thecarriage I3. The screw shaftv I4 at its outer end carries a hand wheel22 having a micrometer drum 23 adjacent an index pointer 24 on a boss 25projecting from the saddle I0, a collar 26 mounted on the screw shaft I4holding the latter in assembly. The handwheel 22 is keyed as at 21 toreduce diameter portion 28 of the screw shaft I4 and secured in positionby the nut 29 threaded thereon. By rotating the handwheel 22, thecarrage I3 may thus be caused to move to and fro along the ways II.

Also mounted upon the bed of the machine (not shown) is a motor 30having a shaft 3l to which a grinding wheel 32 is secured, as by thebolt 33. Optionally the motor 30 may be replaced by a grinding headdriven by a more remotely located source of power. The motor or grindinghead 38 may be swivelled by conventional means so as to vary theposition of the grinding wheel 32 relatively to the workpiece 34.`

Work-supporting fixture construction The work-supporting fixture,generally designated'35, consists of a base 36, bearing .brackets 31bolted as at 38 at intervals thereon and carrying a spindle or arbor 39having an adapter 40 in the end thereof for accommodating the workpiece34. The lbase 36 is secured to the carriage I3 by the bolt 4I having itshead 42 anchored in the T-slot 43 Yin the carriage I3.

The adapter 46 (Fig. 3) is provided with reduced diameter portion 44secured within the axial bore 45 by the set screws 46. piece 34 issecured within the `axial bore 41 by a set `screw 48 the end of whichengages the at portion 49 of a groove 50 (FigsfS and 9) in the shank 5I.A socket 52 in the end of the spindle 39 (Fig. 3) receives the end ofth'e shank 5I. The workpiece 34 is provided with flutes or spiral ridges53 which terminate in cutting lips 54 on the end thereof separated fromone another by the central recess 55. (Figs. 8 and 9.) The iiute 53 isprovided with an edge surface 56 which is backed off as at 51l (Fig. i1)by grinding with the aid of the iixture of the present invention.

The bearing brackets 31 are provided with aligned bores 58y (Fig. 7)through which the spindle or arbor 39 passes. A passageway 59 extendsfrom the bore 58 outwardly and upwardly to the top of the bearingbracket 31. This passageway is iilled with a wiping material 6|), suchas a piece of felt, the lower Surface The work-l i now rotated incooperation with the handwheel` vided withspiral ridges 65 having spiralgrooves 66 therebetween. The spiral grooves 66 are engaged by the end ofa pin 61 (Fig. 1) secured as at 68 in a bore 69 of a bracket 18 boltedas at 1I to the face of a gear-12. The latter is mounted in the groove 13 of the annular bracket 14 secured in the recess 15 in the bed 36 (Fig.

The gear 12 is held in position by the retaining ring 16 bolted as at 11to the annular bracket 14. An adjusting screw 18 is threaded through abore 19 in the annular bracket 14 parallel to the axis of the spindle 39and engages the inner face of the gear 12. The annular. bracket 14 issecured in the recess 'I5 by the bolts 88 passing upwardly through thebase 36,'

and the retaining ring 16 is likewise similarly bolted thereto as at.8I. base 36 is provided with a recess 82 extending transverselythereacross beneath the gear 12.

Mounted in the recess 82 and meshing with the gear 12 is a worm 63 keyedas at 84 (Fig. 2)

to a shaft 85 which is journaled in the bores 86- .and 81 on oppositesides of the. base 3,6.

One end of the shaft 85 carries a. hand wheel 88 by which the shaft 85and worm 83 may be rotated, thereby rotating the gear 12 and swingingthe pin 16 in an arcuatepath around the spindle or arborv39. Mounted onthe outer end. of lthe arbor 39 is a. hand wheel 89, secured thereto bythe stud screw 98 having its inner'end threaded into the bore 9| in theend of -the'arbor or spin dle 39.

Operation In the operation of theinvention, the saddle 'I0 is adjustedup or down and the carriage I3 in or out until the workpiece 34 isproperly positioned relatively to the grinding wheel 32, which 'has alsobeen swivelled so as to betilted at the 89 on the spindle or arbor 39until the edge 56 on a flute 53 of the workpiece 34 is properly pre-`sented to the edge of the grinding wheel 32. The rotation of thehandwheel 88 moves the pin 61 in an arcuate path and thereby shifts thearbor 39 longitudinally for a given point in one of the grooves 66.

With the machine and fixture thus properly adjusted, the hand wheel 22isnow rotated `to feed the workpiece 34 into engagement with the rotatinggrinding `wheel 32. The handwheel 89 is now turned so that the flute 53moves s'pirallyl along the edge of the grinding wheel 32, grinding thespiral portion 51 thereon. (Fig. 11.) When one of the iiutes 53 has thusbeen ground, the handwheel 89 is rotated in the reverse direction untilthe spiral groove 66 is completely freed from and passes beyond the pin61 whereupon At this location thel the operator enters the latter in theend of another of the spiral grooves 66 and turns the hand wheel 89 tofeed another of the flutes53 into engagement with the grinding wheel 32.This is repeated until each of the flutes 53 in turn has been broughtinto engagement with the grinding Wheel 32 and thus ground.

The Workpieces 34 of a given batch Will ordinarily have the flat spots49 located in the same positions relatively to the flutes 53.Occasionally, however, the production of a new batch or run of severalhundred workpieces will cause the flat spot 49 to vary slightlyrelatively to the flutes 53. The latter, however, can be brought intoproper engagement with the grinding wheel 32 merely by rotating thehandwheel 88 in order to swing the adjusting pin 61 up or down in anarcuate path.

Meanwhile the wiping material 60 is occasionally removed from therecesses 59 and the a'brasive dust cleaned 01T the end thereof which isin contact with the surface of the arbor 39. The material 6D is alsooiled occasionally to provide an oil film for the arbor 39, thusfacilitating its rotation and sliding motion.

While a specic embodiment of the invention vhas been described andillustrated, it will be understood that various modifications may bemade within the scope of the appended claims without departing from thespirit of the invention.

What I claim is:

1. A Work-supporting fixture for a machine tool comprising a base plate,bearing means on said base plate, a spindle supported in said bearingmeans for rotary and lengthwise movement, a series of spiral grooves onsaid spindle, a single guide projection engageable with one of saidspiral grooves manual means for selectively moving one of said spiralgrooves into engagement with said projection, and means for adjustablyand arcuately moving said projection about said spindle.

2. A work-supporting xture for a machine tool comprising a base plate,bearing means on said base plate, a spindle supported in `said bearingmeans for rotary and lengthwise movement, a series'of spiralgrooves onsaid spindle, a single indexing projection for engaging one of saidspiral grooves manual means for selectively moving one of said spiralgrooves into engagement with said said ibase plate, a spindle supportedin said bearing means 4for rotary and lengthwise movement, a series ofspiral grooves on one end of said spindle, a single projectionfor'engaging one of said spiral grooves manual means for selectivelymoving one of said spiral grooves into engagement series of spiralgrooves on said spindle, a single projection for engaging one of saidspiral grooves manual means for selectively moving one of said spiralgrooves into engagement with said projec- A tion, an arcuate worm gearencircling said shaft projection, a circular toothed member mounted formovement in an arcuate path and carrying said projection, and a gearengaging said circular toothed member for moving saidtoothed member andprojection about the axis of said spindle.

3. A work-supporting fixture for a machine tool comprising a base plate,bearing means on and carrying said projection, and an adjusting wormrotatably carried by said base meshing with said Worm gear forindependently adjusting the position of said projection about the axisof said spindle. L

5. A work-supporting xture for a machine tool comprising a base plate,bearing means on said base plate, a spindle supported in said bearingmeans for rotary and lengthwise movement, a series of spiral grooves onsaid spindle, a single projection for selectively engaging yone of saidspiral grooves, manual means for disengaging the selected spiral groovesfrom the projection and to progressively positionl another spiral groovein feed contact with said projection a ring gear coaxially mountedrelatively to said spindle and carrying said projection, and anadjusting gear rotatably carried by said base and meshing with said ringgear for arcuately moving said projection in a circular path about theaxis of said spindle.

6. A work-supporting fixture for a machine tool comprising a base plate,bearing means on said base plate, a spindle supported in said bearingmeans for rotary and lengthwise movement, a series of spiral grooves onsaid spindle, a single projection for selectively'engaging one of saidspiral grooves, manual means for moving the spiral grooves progressivelyinto and out of engagement with the projection a ring gear coaxially'mounted relatively to said spindle and carrying said projection, and anadjusting worm rotatably carried by said base and meshing with said ringgear for arcuately moving said projection in a circular path about theaxis of said

